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PubMed (English): Step 4 - Free search terms

Step 3 - Collecting free search terms

You have collected MeSH-terms in the search box. Now you can add free search terms to complete your search. Ready; Click Search Pubmed.
Repeat step 2 and 3 for the other PICO-elements/building blocks.

Why use free search terms?

 The latest articles have not been assigned with MeSH terms, this will take 4-6 months
 You cannot always find an appropiate MeSH-term for your subject
 All definitions concerning a certain subject cannot always be expressed by 1 single MeSH-term
 It can happen that a MeSH-term is not assigned to an article although the article reflects the subject

How to find free search terms

 Do you have a MeSH-term? Use it as a free search term also
 Look at the used MeSH-term for Entry-terms, you will see synonyms
 Use the underlying more specific terms of the used MeSH-term
 Look at already found relevant articles
 Use dictionaries and/or reference books

Search tips

Use the asterisk (*) and find word variations in one single action

​Example: depress* 
Now PubMed searches for all words beginning with depress, zoals depression, depressive, depressed, etc.

 Do not truncate too short; this may lead to Pubmed searching for non-relevant words (NOISE)
• PubMed has a limit of 600 word variations. You will receive an error message when exceeding this number

Does your search term have 2 or more words? Use the double quotation marks  (" ") for the exact word order

Example: "physical therapy"

PubMed only recognises double quotation marks, not the single ones. Use the 
  <shift> key
​• phrasing is optional, not obligatory
​  - too many results? Try phrasing
  - not enough results? remove the quotation marks
 no truncation while phrasing
 sometimes Pubmed does not recognise phrasing, remove the quotation marks

How to search with free search terms

Once you have collected all free search words and put them into your PICO-form, you manually add them to the MeSH terms in the MeSH database searchbox. Click  'Search PubMed' to start the search.


A few points to note:
 Type OR in capitals between each search term, the search terms themselves in small letters
 Add self invented search terms in your searchbox only after you finished your search for MeSH-terms.
  If not, you will lose them.
 Use truncation or phrasing
 A fieldcode may be useful to get the best results

Why using fieldcodes?
If you add a fieldcode to your search terms, Pubmed will only search in this field. Pubmed does not search a whole article. Next to MeSH-terms title and abstract are very telling about the content. By adding [tiab] to your free search words Pubmed will only search in in title or abstract therefore give you a better result.

Be careful, using a field code may limit your search result. Not enough hits; remove the field code.

In addition to [tiab] there are other fieldcodes.
Overview of all fieldcodes | Disclaimer | Over Zuyd Bibliotheek